This invention relates to novel polymer composition having fixed bacterial cells and/or fixed enzymes, in which the enzyme or cells are dispersed within the polymer and to a process for producing the same.
Recently the enzyme industry has become important and has made remarkable progress in producing medicine and food by utilizing enzyme or cells to carry out reactions.
In the prior art the enzyme reaction was effected by using enzyme solution. In this case, however, after the reaction is completed, the enzyme solution employed in the reaction cannot be reused, because the used enzyme solution contains the resulting reaction product. Therefore, since the enzyme solution employed in the one reaction must be removed from the reaction system, the batch system must be used for the enzyme reaction. In other words, in an enzyme reaction using enzyme solution, the maximum effectiveness of the enzyme is not obtained.
In recent years, attempts have been made to prepare an enzyme-polymer composition which could be reused in the enzyme reaction many times. One such composition comprises dispersing the enzyme into a polymeric material or bonding the enzyme to the polymer, and then forming a porous gel or particles from the resulting dispersion. In other words, the research has been directed toward fixing an enzyme or making the enzyme insoluble.
For example, one process for fixing an enzyme comprises dissolving a water-soluble monomer, such as acrylamide, in an aqueous solution of enzyme, and then simultaneously polymerizing and crosslinking the monomer to form a gel comprising the resulting polymer and the enzyme, and evaporating water from the gel to form a porous material.
Another process for fixing an enzyme comprises dissolving a water-soluble polyvinyl alcohol in an enzyme solution and then effecting crosslinking thereof by a known process and evaporating water from the solution to form a porous material. In these processes, the enzyme is dispersed in a water-soluble polymer, whereby the enzyme is fixed or is made insoluble to some extent.
However, the prior processes have the following disadvantages. In these processes, since the monomer to be polymerized as well as the polymer thus formed are water soluble, the polymer composition obtained by the polymerization is a clear gel in which the enzyme and the polymer are dissolved in water. In order to obtain the porous material necessary for carrying out the enzyme reaction from the gel, the large amount of water contained in the gel must be removed. In addition, the porous material obtained by removing water is large lumps comprising a firm, rigid and porous gel, A satisfactory enzyme reaction cannot be effected by using a lumpy gel, because the total surface area of the large lumps is small. Therefore, in order to carry out the enzyme reaction effectively, the large lumps of gel must be ground or pulverized to increase the surface area of the porous material. However, the removal of water from the gel and grinding the large lumps of gel require much time and much labor. In addition, since the polyacrylamide is noxious, a porous material containing the polyacrylamide and the enzyme is not usable in the food industry.
The present invention eliminates these advantages. The present invention provides a porous material obtained by polymerizing a specific monomer containing an enzyme or bacterial cells.